Electric-lighting tube



April 7, 1931- K. WIEGAND I ELECTRIC LIGHTING TUBE Filed Oct. 21 1927INVENTOR' Kurt Wiegand Y ATTORNEY ever,

' ing.

Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE KURT WIEGAND, OFBERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY,

A CORPORATION OF NEW YORK ELECTRIC-LIGHTING TUBE Application filedOctober 21, 1927,

The present invention relates to electric lighting tubes of the kindwherein the electrode container is enclosed in a casing.

In my copending application, Serial No. 226,994, filed October 18, 1927,there is described an electric glow tube, the electrode containers ofwhich are enclosed in a metal casing connected to earth for the purposeof reducing the perforation voltage and having a small spacerequirement, with the interposition of a non-hydroscopic insulation,advantageously with the interposition of glass bodies. In accordancewith the present invention the same purpose is obtained, how- With theomission of a specially made and to be attached metal casing, by the useof an insulating body, say of porcelain, en'- closing the electrodecontainer and which on the outside has a tightly adhering metal coat-The metalcoating is obtained in any desired manner, for example by thesquirting on of liquid metal or in a galvanic way, and gives in the samemanner as the former metal casing, the possibility of applying an earthconnection to the electrode container.

In order to easily attach the box-like insulating body to the electrodecontainer and to be able to also easily inspect the latter, theexteriorly conductively formed insulating i body. consistsadvantageously of two cups of approximately semi-cylindrical shapeengaging with each other and clamped by means of projecting noses. Thescrews serving for the clamping fast of the two cups of the insulatingbody can at the same time be v is connected to 'COIltBJIlGI 1s in thiscase enclosed by a casing- 6 onto the cable used for the connecting upof the earth connection,

In the drawing is shown an example of construction of an enclosedelectrode container of my invention, in longitudinal section in Figure 1and in cross section in Figure 2.

n the forms of construction shown in the main patent the electrodecontainer b attached to the end of the glow tube a has in the interior asheet metal electrode 0, which the cable d. The electrode say ofporcelain, which like insulating body,

one end by the metal cap 1 set is closed off at rubber cap 9 put ontothe glow tube a. The,

casing-like insulating body consists of two approximatelyhalf-cylindrical cups 7: 'n placed together and having interlockingparts comprising the nose-like projections 0 attached to cup 11 whichengage in corresponding recesses on cup n and the lugs p attached to cupn which engage the cup n from the outside. Both cups n, n are furthertightly clamped to each other by the screws 9. The entire outsidesurfaces of both cup parts, W, n of the casing-like insulating body areprovided with a tightly'adhering metal coating 1', which is connected toearth in a suitable manner and advantageously by means of the clampingscrew 1.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1'. An'electric discharge device having an electrode container, aninsulating sheath around said container, and a metallic coating on theexterior surface of said sheath.

2. An electric discharge device having an 1 electrode container, aninsulating sheath around said container, said sheath being formed of aplurality of separable components, and a metallic coating on theexterior surface of said sheath.

3. An electric discharge device having an electrode container, aninsulating sheath 'around said container, said sheath consisting of twosimilar sections and a metallic coating on the exterior surface of saidsheath.

4. An electric discharge device having an electrode container, aninsulating sheath around said container, said sheath being formed of aplurality of separable components, means on said components for holdingsaid components together to form said sheath, and a metallic coating onthe exterior surface of said sheath.

In witness whereof, I have hereunto set my hand this 6th day of October,1927.

' KURT WIEGAND.

d and at the other'end by a

